1-hydroxy-4-halogen-anthraquinone-2-sulfonic-acid and process of making same



Patented Nov. 1, 1932 ERNST HONOLD,OF FRANKFORT-0NTHE-l\IAIN-FECHENHEZM, GERMAN Y, ASSICTNOH, TO

GENERAL ANILrNnwonxs, INC., on NEW YORK,

WARE

N. Y., A CORPORATION OF DELA- 1-HYDROXY-4-HALOGEN-ANTI!RAQUINONE-Z-SULFONIG-AGID AND PROCESS OF MAKING SAME No Drawing. Application filed July 30, 1930, Serial No. 471,896, and in Germany August 28, 1929.

mula

and acting on the diazo-compound thus formed with copper or a copper compound.

Advantageously such an amount of the copper compound is used that the reaction product precipitates in the form of its difiicultly soluble copper salt. By dissolving this salt in an acid l-hydroxy-d-halogen-anthraquinone-Q-sulfonic acid is obtained in a particularly pure state.

It is a surprising fact that by the present process the diazo-group is easily replaced by the hydroxy-group, since the dia-zo-compounds of l-amino--halogen-anthraquinone- Q-sulfonic acids exhibit in acid solution a remarkable stability even at higher temperatures.

The 1-hydroxy-4-halogen-anthraquinone- 2-sulfonic acids thus produced correspondto the formula:

0 NH: 1 l

it lialogen They are valuable intermediates for the production of dyestuffs especially acid wool dyestuffs.

In order to further illustrate my invention ti halogen l the following examples are given, the parts Example 1 parts of the sodium salt of l-aminolbromo-anthraquinone-2-sulfonic acid are diazotized in an aqueous solution as usual and the diazo-compound is isolated. An aqueous paste containing 20-30% of this diazo-compound is slowly introduced while stirring into a solution warmed to 0l00 and consistingof 40 parts of copper sulfate and 600 parts of water. When the evolution of nitrogen has ceased, the copper salt precipitated in the form of brown crystals is filtered 0E and washed. This copper compound is treated with hot water and dilute hydrochloric acid. The solution thus obtained is mixed with common salt. Thereby the sodium salt of 1-hydroxy-4c-bromo-anthraquinone-Q-sulfonic acid of. the formula SOzNa theoretical yield. It represents a yellow powder soluble in concentrated sulfuric acid with an orange-red tint, in water with a yellow tint which turns to dark red on the addition of alkali.

Example 2 Into a suspension of 5 parts of copper powder in 800 parts of water which is warmed to -100", there are slowly introduced while stirring 50 parts of a 50% paste of l-diazo- 4 bromo anthraquinone 2 sulfonic acid.

When the violent evolution of nitrogen has ceased the formed l-hydroxy-L-bromo-anthraquinone-2-sulfonic acid is isolated as sodium salt by the addition of common salt to the filtered solution. The product is identical to that of Example 1.7

The reaction occurs likewise in the presence of free acld.

- Example 3 p 35 parts of the sodium salt of l-aminolchloro-anthraquinone-2-sulfonic acid are converted into the difiicultly soluble diazo-comund by diazotizing in an aqueoussolution. File diam-compound is treated with a hot solution of 25 parts of copper sulfate as dein Example 1. Thereby the crystallized co'pper salt of 1-hydroxy-4-chloro-anthraquinone 2 sulfonic acid is obtained. Zhis compound is converted into the free acid of the formula:

O OH won Y 0'1 b treating it with dilute acid. By the addi ion of common salt its yellow sodium salt is isolated which dissolves in concentrated sulfuric acid with an orange, in water with a V 'ght yellow, in alkalies with a blood-red tint.

I claim: 1. Process which comprises diazotizing a Q 1-amino-4-halogen-anthraquinone-2-sulfonic acid of the formula:

3. Process which comprises diazotizing 1- o- 4- bromo anthraquinone 2 sulfonic acid of the formula:

go and acting on the diazo-compound thus formed with an amount of a copper-compound sufi'lcient for forming the copper salt of the produced 1-hydroxy-4-bromo-anthraquinone-2-sulfonic acid.

4 new compounds the -l-hydroxy-4-w halo en-anthraquinone-2'-sulfonic acids, of the ormula:

halogen which compounds are in the form of their sodium salts soluble in water with yellow tints turning to red on the addition of alkali. 5 As a new compound the 1-hydroxy-4- bromo-anthraquinone-2-sulfonic acid of the e ml w I 0 on which compound is in the form of its sodium salt soluble in water with a yellow tint turning to dark red on the addition of alkali.

In testimony whereof I aifix my signature.

EhNsT HONOLD. 

